Capsaicin inhibits aortic valvular interstitial cell calcification via the redox-sensitive NFκB/AKT/ERK1/2 pathway

Insights into calcific aortic valve stenosis: a comprehensive overview of the disease and advancing treatment strategies

Aortic valve stenosis is a disease characterized by thickening and narrowing of the aortic valve (AV), most commonly due to calcification, which leads to left ventricular outflow obstruction called calcific aortic valve disease (CAVD). CAVD presents as a progressive clinical syndrome with cardiorespiratory symptoms, often with rapid deterioration. The modern-day pathophysiology of CAVD involves a complex interplay of genetic factors, chronic inflammation, lipid deposition, and valve calcification, with early CAVD stages resembling atherosclerosis. Various imaging modalities have been used to evaluate CAVD, with a recent trend of using advanced imaging to measure numerous AV parameters, such as peak jet velocity. Significant improvements in mortality have been achieved with transcatheter AV repair, but numerous therapeutics and modalities are being researched to delay the progression of CAVD. This article aims to provide a comprehensive review of CAVD, explore recent developments, and provide insights into future treatments with various novel modalities.

Capsaicin Attenuates LPS-Induced Acute Lung Injury by Inhibiting Inflammation and Autophagy Through Regulation of the TRPV1/AKT Pathway

Purpose

Acute lung injury (ALI) is a severe pulmonary disease characterized by damage to the alveoli and pulmonary blood vessels, leading to severe impairment of lung function. Studies on the effect of capsaicin (8-methyl-N-geranyl-6-nonamide, CAP) on lipopolysaccharide (LPS)-induced ALI in bronchial epithelial cells transformed with Ad12-SV40 2B (BEAS-2B) are still limited. This study aimed to investigate the effect and specific mechanism by which CAP improves LPS-induced ALI.

Methods

The present study investigated the effect of CAP and the potential underlying mechanisms in LPS-induced ALI in vitro and vivo via RNA sequencing, Western blotting (WB), quantitative real-time reverse transcription PCR (qRT‒PCR), enzyme-linked immunosorbent assay (ELISA), and transmission electron microscopy (TEM). The TRPV1 inhibitor AMG9810 and the AKT agonist SC79 were used to confirm the protective effect of the TRPV1/AKT axis against ALI. The autophagy agonist rapamycin (Rapa) and the autophagy inhibitors 3-methyladenine (3-MA) and bafilomycin A1 (Baf-A1) were used to clarify the characteristics of LPS-induced autophagy.

Results

Our findings demonstrated that CAP effectively suppressed inflammation and autophagy in LPS-induced ALI, both in vivo and in vitro. This mechanism involves regulation by the TRPV1/AKT signaling pathway. By activating TRPV1, CAP reduces the expression of P-AKT, thereby exerting its anti-inflammatory and inhibitory effects on pro-death autophagy. Furthermore, prior administration of CAP provided substantial protection to mice against ALI induced by LPS, reduced the lung wet/dry ratio, decreased proinflammatory cytokine expression, and downregulated LC3 expression.

Conclusion

Taken together, our results indicate that CAP protects against LPS-induced ALI by inhibiting inflammatory responses and autophagic death through the TRPV1/AKT signaling pathway, presenting a novel strategy for ALI therapy.

Niclosamide Inhibits Aortic Valve Interstitial Cell Calcification by Interfering with the GSK-3β/β-Catenin Signaling Pathway

The most common heart valve disorder is calcific aortic valve stenosis (CAVS), which is characterized by a narrowing of the aortic valve. Treatment with the drug molecule, in addition to surgical and transcatheter valve replacement, is the primary focus of researchers in this field. The purpose of this study is to determine whether niclosamide can reduce calcification in aortic valve interstitial cells (VICs). To induce calcification, cells were treated with a pro-calcifying medium (PCM). Different concentrations of niclosamide were added to the PCM-treated cells, and the level of calcification, mRNA, and protein expression of calcification markers was measured. Niclosamide inhibited aortic valve calcification as observed from reduced alizarin red s staining in niclosamide treated VICs and also decreased the mRNA and protein expressions of calcification-specific markers: runt-related transcription factor 2 and osteopontin. Niclosamide also reduced the formation of reactive oxygen species, NADPH oxidase activity and the expression of Nox2 and p22phox. Furthermore, in calcified VICs, niclosamide inhibited the expression of β-catenin and phosphorylated glycogen synthase kinase (GSK-3β), as well as the phosphorylation of AKT and ERK. Taken together, our findings suggest that niclosamide may alleviate PCM-induced calcification, at least in part, by targeting oxidative stress mediated GSK-3β/β-catenin signaling pathway via inhibiting activation of AKT and ERK, and may be a potential treatment for CAVS.